Limiting reagent question

[dnovikov]

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I am kind of confused about the answer, the question is as follows:

what is the limiting reagen when 22 grams of C3H8 are mixed with 48 grams of O2?

C3H8 + O2 --> CO2 + H2O

The correct answer is "oxygen is the limiting reagent". Can anyone please elaborate? Couldn't understand the explanation as given in the TBR book...

 

[Ssina]

I am kind of confused about the answer, the question is as follows:

what is the limiting reagen when 22 grams of C3H8 are mixed with 48 grams of O2?

C3H8 + O2 --> CO2 + H2O

The correct answer is "oxygen is the limiting reagent". Can anyone please elaborate? Couldn't understand the explanation as given in the TBR book...

the reaction is not balanced, so you have to balance it first, which gives you:

C3H8 + 5O2---> 3 CO2 + 4H2O

and getting the moles from the question: we have 0.5moles of C3H8 (22g/44g/mole) and 1.5 (48g/32g/mole) moles of O2..... since for 1mole of C3H5 we need 5 moles of O2, for 0.5 moles we need 2.5moles of O2, but here we have only 1.5... so O2 is the limiting reagent. (I think you maybe forgot to balance the reaction first)

 

[dnovikov]

Thanks I got it now, you're wording is a lot easier to understand than the explanation.